The concept of this proposal is to test the validity of the use of insects as animal models of aging. By means of a microcomputer, an optical sensing device, and assembly-language programs written by the P.I., the spontaneous motor activity of large numbers of individual Drosophila melanogaster will be followed in a longitudinal study. The data collected will be processed by computer and analyzed for time-dependent changes such as change in total activity, diurnal rhythms, speed of locomotion, and preference for different self-selected environments. The initial studies will document behavioral changes with aging, as insects will be permitted to move spontaneously in their chambers and an entire life table of their activities will be monitored. The data will be analyzed by numerous statistical procedures as a function of age of the insect and, retrospectively, as a function of time prior to death. Correlations found in the latter analysis are potential biomarkers of aging. The initial findings will serve as a baseline to develop behavioral predictors of aging or impending death. Once these are known, it will be possible to run automated, large-population, rapid assessment of the effects of various treatments (additives to diets, exposure to different environmental and social stimuli). By this means common theories of aging can be tested and evaluated, and clinical and pharmacological screening procedures can be established. The basic protocol outlined here can be easily adapted to similar studies using other suitable animal models such as rodents.